Apparatus for launching or assisting in the launching of airplanes



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June 26, 1945.v G. T. WILSON .'5 Sheets-Sheet l Filed Jan. 22, 1942 June 26, 1945. G. T. wlLsoN APPARATUS FOR LAUNCHING OR ASSISTING IN THE' LAUNCHING OF AIRPLANES Filed Jan. 22, 1942 3 Sheets-Sheet 2 June 26, 1945. G. T. WILSON 2,379,267

APPARATUS FOR LAUNCHING OR AS-SISTING IN THE LAUNCHING OF AIRPLANES Filed Jan; 22, 1942 3 Sheets-Sheet 3 #Tram/Ey Patented June 26, 1945 APPARATUS FOR LAUNCHING OR ASSIST- ING IN THE LAUNCHING OF AIRPLANES Gilbert Thomas Wilson, Karori, Wellington,

New Zealand Application January 22, 1942, Serial No. 427,804

In New Zealand February 20, 1941 H Claims.

It is well-known that considerably more power is required to launch an airplane into the air than is required to maintain it in normal flight. This is particularly so where the ying eld is of limited area. Y

It `is also well known that for any increase in the rate of acceleration of an airplane on the ground there is a corresponding reduction in the length of run-way required for taking off.

Launching means at present employed for assisting in the launching of airplanes are not capable of launching heavily laden airplanes at a suiiicient rate of acceleration with the result that there is an undue limitation on the loads that airplanes can leave the ground with for a given length of run-way. f

This invention relates to methods of, and means for, launching or assisting inthe launching of an airplane, and aims to provide improvements therein which will considerably increase the acceleration of the airplane on the ground and thus enable the plane to take off with a much greater load than is possible when the airplane, is launchedA in any known manner. The invention also enables a shorter run-way to be employed for a. given loading of the airplane.

It will be realized that an increase in the possible loading of a plane will, if taken advantage of to carry `extra fuel, give a longer range. On the other hand, for commercial and wartime purposes, a plane could be launched with a greater pay-load or a greater load of explosives, as the case may be.

The invention consists in apparatus for launching or assisting in the launching of an airplane, comprising a power unit, a heavy i'lywheel driven from said power unit through an electro-magnetic slip coupling, an electro-magnetic slip coupling between said flywheel and the driving sheaves of multiple cable launching means, means to controllably energise said electro-magnetic slip couplings when desired, a carriage actuable by said cable launching means and adapted to propel the airplane and braking means to stop the carriage when desired.

The invention will now be described with reference to the accompanying diagrammatic drawings, in which:

YFigure 1 is a vertical section through an underground room containing the operating mechanism of one form of launching means according to the invention,

Figure 2 is a diagram illustrating a preferred run-way contour employing ramps,

Figure 3 is a cross-section through thevunderground tunnel employed in the construction shown in Figure 1, showing one of the columns carrying the intermediate cable-supporting sheaves, y

Figure 4 is a longitudinalA part section through the tunnel, showing a side view of one of said columns,

Figure 5 is a cross-section through the tunnel, showing how the cable-tensioning sheaves at theend of the run-way opposite to the driving end are mounted'.

Figure 6 is a longitudinal part-section on the line A-B Figure 5,

Figure 7 is a cross-section through the tunnel, showing one of a series of intermediate tensioning sheaves for independently evening up each cable and thus ensuring an even load on each cable,

Figure 8 is a longitudinal part-section through the tunnel, on the line CD, Figure '7, and

Figure 9 is a diagram illustrating a possible circuit layout for controlling the drive to ,the cables.

A run-way I is provided disposed in the direction of the prevailing wind at the particular flying ield. The run-way may be from 600 feet to 1200 feet in length and may have two small ramps 2, one at each end, the grade of which may be 1 in 20, the object of the two ramps being to assist the airplane in taking 01T, which may beV in either direction along the run-way. according to the direction of the Wind.

The run-way may' be Alaid out so that the top of each ramp is say about feet from the nearest end of the run-Way, the ramps having the same slope on either side and a level runway being provided between them.

Provision may be made to light the run-way, both ilood and signal lights may be provided for night operation.

I prefer to provide the run-way in such a position as to leave the main area of the aerodrome clear for landing and other purposes.

I believe it is best to house the operating mechanism below the ground as shown, although this is not absolutely necessary. It has the advantage that other aircraft can take off across the run-way when the launching mechanism is not in use.

A slot 3 is formed longitudinally of the runway, said slot communicatingr with a longitudi- -nal tunnel 4 beneath the runway and being dened by angle metal protecting plates 3a. The tunnel contains cables 5, sheaves for said cables,

preferably "adapted to engage behind the under,A

carriage of the airplane 8 or a member assounit 24 (which may be an electric motor or an internal combustion engine or steam engine) is coupled to a heavy ywheel 25 (say 10 tons in weight and having a steel rim and web to with` stand the great centrifugal force it has to contend with). In the case of an electric motor or 'other power unit which cannot take the load up'at once, the` coupling ris effected through the ciated therewith, or the airplane may rest on the i carriage, a stop being provided to engage behind the wheels of the airplane. In either case the airplane is free to rise when it reaches flying speed. Preferably the bearings 9 by which the axles l of the carriage are carried are of thel The method of actu.

Timken or a similar type. ating the carriage will be hereinafter described.

At or near each end of the carriage, a member Il projects downwards through the longitudinal slot 3 into the tunnel and is there connected toa plurality of cables running lengthwise of thetunnel,` such cables being continuous and being looped around driving sheaves l2 at one vend of the tunnel and around tension sheaves I3 at the other end .of the tunnel.

'For normal use, I may employ about four nexible cables of no larger than 5/8 inch diameter (each witha breaking strain `of not less than 12.5 tons). It will be understood howeverv that the diameters of the cables andthe breaking strain will vary according to the maximum load to `be imposed thereon.

vThe cables are spaced horizontally and rest at intervals, in the tunnel upon intermediate cable-supporting sheaves ld mounted preferably upon `spindles II5 carried by upright columns I6 located centrally or at one side or other of the tunnel. The use of several small wire ropes instead -of a single cable provides suflicient flexibility to ensure adhesion tothe sheaves at high speed. v v

.The cable-tensioning sheaves I3 at the end of the run-way opposite to the driving end are providedV to keep the cables under the desired tension and, limit whipping when the drive is suddenly changed from full-speed to braking and stopping. Such cable-tensioning sheaves may be mounted to a spindle `l1 carried by a slide I8` which is longitudinally adjustable `in either direction along rails i9 and which has connected thereto a tensioning cable or cables 20 passing over a pulley orrpulleys 2| into `a pit 22 where ,a weight or Weights 23 is or are provided on 'th lower end Vor endsthereof.

Independent tensioning `sheaves are preferably employed to independentlyeven up Ieach cable and thus ensure even load on the same. In the construction shown in Figures '1 and 8, at spaced intervals. along the tunnel there are provided four independent tensioning sheaves 34, each supportedvfrom twovertical uprights which may be connected together at their upper ends as at 3|. vThe uprights are provided with vertical slots 32` in which bearings 33 slide vertically, said bearings carrying ahorizontal shaft 33a on which ,is mounted the sheave 34. The bearings are spring-loaded yas at 35 so that the sheave exerts a downward pressure on the lower stretch of one of the cables 5 and, by putting abend in sametensions it independently of the other cables. One of the other three cables passes Ifreely between the uprights 30 and the other two cables are disposed outside saine.

,p At Yme driving, ,end ,ofthe runrwan Power,- v i medium of a suitable slip coupling'26. This coupling is of the electro-magnetic type and is controllably energised from a suitable D. C. electric power source, consisting of for instance a suitably'driven D. C. generator. The slipping enables the power unit 24 to work at a satisfactory operating speed while the wheel 25 is reaching normal speed of say about 750 R. P. M. and while `the said wheelisslovving down under load.

` It will `be, clear that the electro-magnetic slipcoupling 25 could be replaced by some other flexible coupling such as a fluid flywheel.

. `A flexible coupling between the power unit and the wheel 25 .would not be essential if the power unit consistsof a steam engine. g

`The vflywheel 'e355I is connected to the driving sheaves l2 through the medium of aI second electro-magnetic Aslip-coupling `21 which can be readily controlled to ,g transmit the drive at will, so that when the coupling 21 is energised by a suitable D. C. source (which may be the source mentioned earlier herein) it will transmit the kinetic energy stored in the flywheel 25, and also a substantial yportiony of the torquey exerted by the power unitin rotating the said flywheel 25, to the cables 5f. v

I propose to employ large-surface brakes 28 to stop the carriage 6 and the cables 5.` (It will be ,realised lthat only the calo1esand` the carriage require, to be stopped Iby-the brakes. The heavy flywheel V25 and power unit 24 still run on to be `shut down atanyvconvenient time.)

I maydividefthe cables 5 into two groups 4of two cables, and carrylthe two groups by separate driving,V supporting and 'tensioning sheaves, as shown. Each `drivingnjand tensioning 4sheave aroundwhich a cable isflooped may then have a brake acting thereon. .j A l v The aforesaid small D. C. generator employed vto 'energise the .A electrofmagnetic slip couplings .26 and 21V may 4also be kemployed to energise solenoids releasingv the brakes. The dual function of releasing the brakes and energising the electro-magnetic slipl coupling 21. between the wheel Aand the driving sheaves is preferably achieved through a, single control which `releases the brakes and energises the slip coupling 21 in V the oneoperation. The Icontrol vswitch for this purpose,vv could be underrthecontrol of the pilot who could .start the-cables inmotion by operating a button switch on a flex .cable (as the current for the electro-magnetic -slip coupling 21 is not very large). When he has pressed the button, the pilot could throw same and the attached flex clear of the plane and kcarriage 6. The switch on the flex cable could be located in a starting circuitso that closingV of the ,said switch on the ilex cable'closes a remote controlled switch on the main D.C.4circuit i The stopping of the carriage fcould be controlled by a control operable by such carriage reaching a predeterminedyspeed, or by various distances'of'run. ',Whiche'v'er `method of stopping the carriage is employed; `the electromagnetic slip-coupling 21 between thewheel 25 and the driving sheaves l2 would fout and the l, The circuit arrangement shown diagrammatically in Figure 9 is designed so that theelectromagnetic slip coupling 21 will be de-energised and the solenoid brakes 28 applied when the carriage has reached a predetermined speed. 'Ihe brake solenoids and the slip-coupling 21 are connected in parallel to the leads 36.-and.31 respec- In the main D. C. circuit there is interposed a double pole switch 44-45 which is held closed under spring pressure during launching operations and opened simultaneously by means to be hereinafter described so as to open the main D. C. circuit and thus discontinue the drive and apply the brakes.

The switch 44-45 is held open by means of a pawl 40 which preferably has a rounded upper end engaging beneath a projection on the switch rod 4l. To release the pawl from the projection for starting purposes, said pawl may have pivoted to it a rod 42 of a solenoid 43 which is located in a starting circuit part of which is coincident with the main D. C. circuit so that the starting circuit is beyond the control of the switch 44-45 but under the control of the main switch 39. Thevsolenoid 43 is spring-loaded so that when the starting circuit is open, said spring holds the pawl 4U towards the switch rod 4l.

In the starting circuit is located a springreturned switch 41 the closing of which releases the pawl 40 to permit the switch 44--45 to close under the spring pressure, the brakes being thus released and the slip coupling 21 being energised to drive the sheaves 1,2. The switch 41 is preferably a button switch under the control of the pilot as previously suggested.

The means to open the main D. C. circuit for stopping purposes vmay comprise an impulse solenoid 46 actuating the switch rod 4I, said solenoid 46 being energised from a stopping circuit i.

52 part of which is coincident with the main D. C. circuit so that when the switch 44-45 is open the stopping circuit is open. The stopping circuit is closed in the following way:

At spaced points along the `run-way, say at about 100 feet intervals, there'are provided depression switches 43, 48a, 48h, 48e and 48d which are adapted to be closed by a wheel of the carriage passing thereover. Each depression switch is spring-loaded to return same, but its upward ,l

return movement is damped by a fluid dash-pot 49. The depression switches 48 and 48d are each adapted when depressed .to'engage two contacts and the other depression switches 48a, 48h, and 48e are adapted to engage three contacts.

Two leads 50 and 5l are provided in the stopping circuit and alternate depression switches have one contact connected to the lead .50, one contact of each of the other switches being connected to the other lead 5I.

The remaining `contacts of the depression switches are connected to the remaining contacts and therebyde-energise the coupling 21 and the brake solenoids. It will therefore beobvious that the closing of the stopping circuit is dependent on the speed of the carriage or member carrying the airplane.

On the opening of the switch 44-45 the pawl `40 comes into operation to keep the said switch open until the solenoid 43 is operated to release the switch 44-45 and thus permit same to close.

An advantage of providing for the stopping circuit to be subject to the control of the switch 44--4'5 is that immediately the stopping circuit is closed the switch 44-45 opens, and the stopping circuit is then open when the depression switches open again, arcing at the contacts of the depression switches being thus minimised.

A single pole switch could be employed instead of the double-pole switch 44-45, the use of the double-pole switch however minimising arcing on the opening of the main D. C. circuit.

In Figure 9 I show means which may be provided so that the drive will be discontinued and the brakes will be applied on the carriage reaching any one of a series of predetermined points. For this purpose I provide a series of short-circuiting switches a, b, c, d, and e so' connected vin the circuit that operation of any one of such switches provides for the stopping circuit to` be closed on the operation of a single correspondn ing depression switch, so that it is unnecessary for two depression switches to be closed together for the said circuit to be closed.

The short-circuiting switches, which when closed will result in the closing of the stopping circuit when the depression switches 48l 48a, 48h, 48e and 48d are closed, are the switches a, b, c, d, and e, respectively.

The distance which the carriage or member will travel before stopping depends on which of the switches a, b, c, d or e are closed. It will be obvious that if any of the short-circuiting switches c, d, or e are closed the stopping circuit will be lclosedA either on the closing of any two adjacent depression switches preceding the depression switch which co-acts with the closed short-circuitilng switch to close the said circuit, or on the closing of the depression switch which with the closed short-circuiting switch closes such circuit, depending on the rate of acceleration of the airplane.

The depression switches may be of any known reliable type giving the desired degree of damping, and the number employed along the run-way may be varied according to requirements.

Any other suitable means may be employed to close the stopping circuit when the airplane has reached a predetermined point. A simple switch which when closed remains closed-.until manually opened could be employed.

The carriage 6 may be returned by a small motor driving the driving sheaves I2 through a controllable slip coupling 29 in the reverse direc-k tion to that in which they are driven by the wheel 25, and the control means for driving such ref versing motor may be arranged to automatically release the solenoid brakes 28. Such control means must not however energise the electromagnetic slip coupling 21,

In Figure 9 is shown a switch 53 which if opened will permit the carriage to be returned on the closing of the switch 39, the releasing of the pawl 40 from the projection on the rod 4I and the closing of the circuits through the reversing motor and the coupling 29.

In the main underground motor room may be the electro-magnetic slip coupling 21.

the manually operable switches which must be accessible in normal operation mayI be above ground. The underground motor room may -be locked normally to prevent interference-with'the .apparatus therein contained.

Y Owing fto the considerable strain which the driving mechanism meets with in operation, I prefer that as a precautionary measure the primary electro-magnetic slipcoupling 2S should be capable of transmitting between50% and 100% in excess `of the power developed by .the power unit. The secondary electro-magnetic slip coupling. 21 may bedesigned to transmit about four times the power actually developedf'by thepower unit, to permit it to transmitefliciently thepower stored upin the wheel 25y and a substantial part of the torque applied by the power unit in Y rotating the said wheel.

By my invention, the power actually applied to the cables 5 by the wheel 25 may be boosted up to :for instance anywhere between 200% and 400% of the Ypower actually developed by the power unit.

The electro-magnetic slip-couplings 2S and `2l and 29 may ibe of a type similar to those used `in geared Diesel engines for marine propulsion.

In operation, with the construction shown in. the drawings, the lpo-wer unit Z4 is started up and theelectro-rnagnetic slip coupling 26 is energised. When the wheel is rotating at maximum speed and it is desired to launch an airplane, the said airplane, with its motor running, is placed in position so thatthe carriage 6 `will carry same with it along the run-way, .and the pilot simultaneously opens the throttle and operates the button switch, thus closing the switch 44-45 and thereby releasing the brakes 28 and energising The stored up energy in the wheel 25 is immediately made available, and, supplemented by atleast a substantial part of the driving torque `of the power unit 24, it assists the plane along the runway. The secondary electro-magnetic slip-coupling 21 enables smooth and rapid acceleration of the carriage. During accelerationv of thev lcarriage 6 the heavy wheel 25 slows down to an extent depending on the extent to which Aits stored energy is utilised to assist the launching.

When the plane reaches the summit ofthe Vseeond ramp, or before then, by `which time it may be travelling at isay about 70 M. P. H., `it is launched and is free to leave the carriage yl5 which is braked and stopped byfeither of the methods previouslydescribed, :the `carraige being then returned. The secondary `electro-magnetic slip coupling 21 does not transmit any drive at this stage, even though the power unit 24 may be operating. l v

The power unit 24 maybe stopped whenwdesired.

`To `launch in the reverse direction, the ,main motor is :reversedy the carriage being started at the opposite end of the run-way. It will be obvious `that when the airplane is being launched towards the end tensioning-sheaves the horizontal pull on .said sheaves requires a considerable resistance to counteract it, and such resistance is applied by employing balance weights 23 ofthe 'mounted the solenoid switchapparatus, and all constructions embodying the invention, what I claim is:

1. Apparatus for launching or assisting in the launching of an airplane; comprising a power uni-l1; a heavy flywheel, an electro-magnetic slip coupling for driving said flywheel from said power unit; multiple cable launching means including driving sheaves; an electro-magnetic slip coupling between said iiywheel and the driving sheaves; means to controllably energise said electro-magnetic slip couplings when desired, including a main D. C. circuit having therein the energising circuit of the slip coupling between the flywheel and the driving sheaves; a carriage actuable by said cable launching means and adapted to propel the airplane; a track along which said carriage runs; and braking means to stop the carriage, including a stopping circuit, a series of depression switches in said stopping circuit located adjacent to the track so as to be closed in succession by the carriage passing along the track, and hydraulically damped spring return means for said depression switches, the stopping circuit being closed on the carriage `closing a depression switch before the immediately preceding depression switch has opened, an impulsesolenoid operated remote-controlled switch operable by clos-ing `of said stopping circuit to open the main D. C. circuit, Solenoid brake-releasing means comprising an energisingrcircuit located in the main D. C. circuit so that opening of said main D. C. circuit de-energises said slip-coupling between the ilywheel and the driving sheaves and applies the braking means to stop the carriage, and means .to maintain the main D, C. circuit open until again closed.

2. Apparatus for 'launching or assisting in the launching of an airplane; comprising a power unit; a heavy ilywheel; an electro-magnetic slip coupling `for driving said ilywheel from said power unit; multiple cable launching means including driving sheaves; an electro-magnetic slip coupling between said flywheel and the driving sheaves; means to controllably energise said electro-magnetic slip couplings when desired, including a main D. C. circuit lhaving therein the .energisingcircuit of `the slip coupling between 'the ilywheel and the driving sheaves; a carriage actuable iby said cable `launching means and adapted to propel the airplane; a track along whichsaid carriage runs; braking means to stop the carriage, including la stopping circuit, a series of depression switches in said stopping circuit located Aadjacent Vto the track so as to be closed in succession by the carriage passing along the track, and `hydraulically damped spring return means .for said `depression switches, the stopping circuit :being closed on the carriage closing a `depression rswitch `before Athe immediately preceding depression switch -has opened, an impulse solenoid operated remote-controlled switch operable by'closing of said stopping circuit to open the mai-n D, C. circuit, .solenoid brake-releasing means the energising circuit of 4which is located in the main D. C. circuit Aso that opening of said main D. C. circuit de-energises said lslip-coupling 'between the ilywheel and 'the'driving sheaves and applies the brakingmeans to stop the carriage, :and means .-to maintain 'the main D. C. circuit open untilagain closed; and switching;means whereby'when desiredthe carriage can be stopped Von reaching .a vpredetermined point irrespective fof the `speed of said carriage.

3. Apparatus forlaunching or assisting inthe launching `of an airplane; comprising -a power unit; a heavy flywheel; an electro-magnetic slipcoupling forldriving said flywheel'from said power unit; multiple cable launching Vmeans including driving sheaves; an electro-magnetic slip-coupling between said ilywheel and the driving sheaves; means to'controllably energise said electro-magnetic slip couplings when desired, including a main D, C. circuit having therein the energising circuit of the slip coupling between the iiywheel and the driving sheaves; a carriage actuable by said cable launching means and adapted to propel the airplane; a track along which said carriage runs; braking means to stop the carriage, includinga stopping circuit, a series of depression vswitches in Said stopping circuit located adjacent to the track so as to be closed in succession by the carriage passing along the track, hydraulically damped spring return means for said depression switches,l the stopping `circuit being closed on the carriage closing a depression switch before the immediately preceding depression switch has opened, a spring closed remote controlled impulse-solenoid operated switch opened by closing of said circuit to open the main D. C. circuit and the stopping circuit, solenoid brake releasing means the energising circuit of which is located in the main D. C. circuit so that opening of said main D. C. circuit de-energises said slip coupling between the flywheel and the driving sheaves and applies the braking means to stop the carriage, and releasable means to maintain the said remote-controlled solenoid operated switch open until again closed.

4. Apparatus for launching or assisting in the launching of an airplane; comprising a power unit; a heavy ilywheel; an electro-magnetic slip coupling for driving saidflywheel from said power unit; multiple-cable launching means including driving sheaves; an electro-magnetic slip-coupling between said ywheel and the driving sheaves means to controllably energize said elec* tro-magnetic slip couplings when desired, including a main D. C. circuit having therein the enM ergising circuit of the slip coupling between the ywheel and the driving sheaves, a starting circuit, a switch therein, a solenoid energised by the closing of said starting circuit, and release means operable by the energising of said latter solenoid; a carriage actuable by said c'able launching means and adapted to propel the airplane; a track along which said carriage runs; braking means to stop the carriage, including a stopping circuit, a series of depression switches in said stopping circuit located adjacent to the track so as to be closed in succession by the carriage passing along the track, hydraulically damped spring return means for said depression switches, the stopping circuit being closed on the carriage closinga depression switch before the immediately preceding depression switch has opened, a spring-closed remote-controlled impulse solenoid operated switch opened by closing of said circuit to open the main D. C. circuit and the stopping circuit, solenoid brake releasing means the energising circuit of which is located in the main D. C. circuit so that opening of said main D. C. circuit de-energises said slipcoupling between the iiywheel and the driving sheaves and applies the braking means to stop the carriage, and releasable means to maintain the said re mote-controlled solenoid operated switch open until again closed, said releasable means being released by the aforesaid release means, to enable the remote-controlled solenoid operated switch to close andl the slip coupling and brake solenoids t0 be energised.

5. Apparatus forlaunching or assisting in the launching of an airplane; comprising a power unit; a heavy ywheel; an electro-magnetic slip coupling for driving said ywheel from said power unit; multiple cable launching means including driving sheaves; an electro-magnetic yslip coupling between lsaid flywheel and the driving sheaves; means to controllably energise said electroamagnetic slip couplings when desired, including a main D.IC. eircuithaving therein the energising circuit of the slip coupling between the flywheel and the driving sheaves, a starting circuit, a button switch on a ex cable in said starting circuit. said switch being under the control of the pilot, a solenoid energised by the closing of said starting circuit, and release means operable by the energising of said latter solenoid; a carriage actuable by said cable launching means and adapted to propel the airn plane; a track along which said carriageruns; braking means to stop the carriage, including a stopping circuit, a series of depression switches in said stopping circuit located adjacent to the track 4so as to be closed in succession by the carriage passing along the track, hydraulically damped spring return means for said depression switches, the stopping circuit being closed on the carriage closing a depression switch before the immediately preceding depression switch has opened, a spring closed remote-controlled impulse-solenoid operated switch opened by closing of said circuit to open the main D. C. circuit and the stopping circuit, solenoid brake-releasing means the energizing circuit of which is located in the main D. C. circuit so that opening of said main D. C. circuit de-energises said slip coupling between the flywheel and the driving sheaves and applies the brakes to stop the carriage, and rev leasable means to maintain the said remote-controlled solenoid operated switch open until again closed.

6. Apparatus for launching or assisting in the l launching of an airplane, as claimed in claim l,

the said carriage being provided withv a dependent connection attached to the cables of said multiple cable launching means, said cables passing around the driving sheaves at or adjacent to one end of the runway and around other sheaves at or adjacent to the opposite end of the runway, said cables being supported intermediate of the ends of the runway on spaced supports and the drivingsheaves being secured to a shaft secured in turn to the driven member of the slip coupling driven by the heavy ilywheel.

'7. Apparatus for launching or assisting in the launching of an airplane, as claimed in claim l, the said carriage being provided with a dependent connection attached to the cables of said multiple cable launching means, said cables passing around the driving sheaves at or adjacent to one end of the runway and around other sheaves at or adjacent to the opposite end of the runway,

said cables being supported intermediate of the ends of the runway on spaced supports and the driving sheaves being secured to a shaft secured in turn to the driven member of the slip coupling driven by the heavy flywheel, the driving sheaves and the sheaves at or near the opposite end of the runway being fitted with the braking means for stopping the carriage.

8. Apparatus for launching or assisting in the launching of an airplane, as claimed in claim l, the said carriage being provided with a dependent connection attached tov the cables of said multiple launching means, said cables passing around the driving. sheaves at or adjacent to one endy of the runway and around other sheaves at or adjacent to the opposite end of the runway, said cables being supported intermediate of the ends of the runway on spaced supports and the driving rsheaves being secured to a. shaft secured in turn to the driven member of the slip coupling driven bythe heavy iiywheel, the driving sheaves and the sheaves at or near the opposite end of the runway being tted with the braking means for stopping the carriage, the sheaves at the opposite end of the runway to the driving. sheaves being tensioning sheaves. y

9. Apparatus for launching or assisting in the launching of an airplane, as claimed in claim 1, the said carriage being provided with adependent connection attached to the cables of said multipleV launching means, said cables passing around the driving sheaves at or adjacent to one end of therrunway and around other sheaves at or adjacent to the opposite end of the runway,

said cables beingy supported intermediate of the ends of the runway on spaced supports and the driving sheaves being secured to a shaft secured in turn to the driven member of the slip coupling driven'r bythe heavy flywheel, the driving sheaves and the sheaves atl or near the opposite end of the runway'beingv tted` with the braking means for stopping the carriage, the sheaves at the opposite end ofthe runway to the driving sheaves being tensioning sheaves and independent tensiom'ng means being provided `to independently tensionthe cables.

l0. Apparatus for launching or assisting in the launching. of an airplane, a-s claimed in claim 1, comprising also an independent reversing motor connected to the driving sheaves tobring the carriage back to starting position after 1aunch ing an airplane, independent control means for thev said reversing motor adapted' to aut0matically release the brakes, and a controllable slip coupling between said reversing motor and the driving sheaves. i

GILBERT THOMAS WILSON. 

